A personal digital assistant (PDA) is typically a handheld device that can store and organize personal information for a user. For example, a PDA may store contact information, such as addresses and phone numbers of friends. For example, a PDA may organize calendar information, such as appointments, meetings, etc. For example, a PDA may store notes in text, record a voice message, take a photo, etc.
Some PDAs are integrated with cellular phones as smart phones. The portability and the rich functionalities of smart phones can provide great assistance to the user in daily life. For example, using a smart phone, a user can search for a phone number of a friend in an address book, make a phone call to the friend, and record an appointment or meeting.
Some PDAs can further provide navigation assistance using an integrated Global Positioning System (GPS) receiver; and some PDAs further have wireless communications capabilities for accessing Internet, such as browsing web pages, receiving and sending emails, etc.